鼠类-天敌系统渐近稳定性的数学分析

天敌能否控制鼠害是鼠害防治实践中最重要的课题之一,通过建立鼠类--天敌系统的捕食--食饵离散模型,推导出自然生态条件下鼠类数量与天敌数量的平衡关系以及鼠类--天敌系统渐近稳定的判定条件,数学分析表明,天敌对鼠的数值反应、功能反应以及鼠类种群繁殖调节是系统能够渐近稳定的决定因素。     

天敌对害鼠种群控制作用的研究进展

国内学者应用“天敌”这一概念,一般指某类动物的捕食者(predator)。对于害鼠与其天敌的关系的研究,历来是国际生态学界的重要课题。近年来,由于鼠害防治等生产实践的需要,我国学者也逐渐开始了这方面的工作。     

鼠害治理条件下鼠类群落变动的生态过程

在高寒草甸鼠害治理过程中,因治理方式、强度以及环境的差异,鼠类群落的变动表现出不同的特点。次生植被地区,灭杀高原鼢鼠和高原鼠兔后,经补播、封育、灭杀残存高原鼢鼠等综合治理,５年内,高原鼢鼠和高原鼠兔种群数量显著低于灭杀前（Ｐ＜０．０５）,根田鼠和甘肃鼠兔种群数量剧烈波动,鼠类群落多样性、均匀度指数年间波动大,群落不稳定;仅使用药物灭杀高原鼢鼠和高原鼠兔,３年后,高原鼢鼠种群数量与灭杀前无显著差异（Ｐ＞０．０５）,鼠类群落多样性、均匀度指数在灭鼠当年下降,以后各年间变动不显著。原生植被地区,使用药物灭杀高原鼠兔,高原鼢鼠种群数量上升,围栏封育措施,对高原鼠兔种群的增长有显著的抑制作用（Ｐ＜０．０５）,但对高原鼢鼠作用不显著（Ｐ＞０．０５）;单一药物灭杀高原鼠兔,鼠类群落多样性、均匀度指数无显著变化,灭杀３年后,高原鼠兔种群数量与灭杀前无显著差异（Ｐ＞０．０５）,高原鼢鼠显著增加（Ｐ＜０．０５）。人工大量捕杀高原鼢鼠,非围栏封育地区,高原鼠兔种群显著增加（Ｐ＜０．０５）。     

小麦不同品种上麦蚜及其天敌的数量变动

试验结果表明小麦品种 (系 )的抗性对麦蚜种群数量影响很大 ,百株蚜量随着小麦品种抗性增强而下降。而同一小麦品种对不同种蚜虫的抗性存在质的差异 ,铭贤 1 69品种 ,蚜高峰期百株蚜量麦长管蚜 63 0头 ,禾谷缢管蚜只有 1 1 5头 ,两者相差 5 5倍。另一方面 ,小麦品种抗性对麦田天敌的种群数量影响不大 ,而对天敌的发生期有些影响。因此 ,小麦品种抗性、天敌对麦蚜的自然控制能力 ,可把小麦中后期的蚜虫虫口密度控制在经济损失允许水平之下。     

棉蚜与其天敌种群分布格局的关系

对棉蚜与其多种天敌在数、时、空方面关系的研究表明,龟纹瓢虫与棉蚜种群数量极相关,两者发生数量高峰期和低谷期均是同步的,龟纹瓢虫对棉蚜种群有明显的控制作用,龟纹瓢虫、草间小黑株及棉蚜种群的三维空间格乙为聚集型,棉蚜和草间小黑蚜个体间互相吸引,龟纹瓢虫个体间互相排斥。     

一个确定害虫天敌最佳饲养数量的数学方法

以Ｉｔｏ随机微分方程为工具,研究了昆虫种群因环境因素变化产生随机波动情况下的数量变化规律;利用求极小值的方法,给出了生物防治中确定天敌最佳饲养数量的计算公式,指出了确定公式中参数的统计方法。     

石榴园棉蚜及其天敌之间的关系

采用灰色系统分析方法,分析了对主要害虫棉蚜及其天敌日捕食总量之间关联度,结果表明,棉蚜群落中与其关联度较高的天敌种类依次为肖蛸蛛(0．8607)、中华草蛉(0．8058)、八斑球腹蛛(0．7989)、异色瓢虫(0．7881)和大草蛉(0．7758),与理想天敌日捕食总量间关联度较高的天敌种类为草间小黑蛛(0.8975)、智利小绥螨(0．8132)、龟纹瓢虫(0.7806)和大草蛉(0．7669);与天敌数量间关联度较高的天敌依次为草间小黑蛛(0．8482)、中华草蛉(0．7533)、肖蛸蛛(0．7532)、八斑球腹蛛(0．7411)和大草蛉(0．7116),与理想天敌数量间关联度较高的为草间小黑蛛(0．8461)、智利小绥螨(0．7325)、龟纹瓢虫(0．6983)、大草蛉(0．6815)和中华草蛉(0．6757)．棉蚜垂直生态位和水平生态位的重迭值均>0．9567的天敌有草间小黑蛛、大草蛉和肖蛸蛛;时间生态位重迭值>0．4020的天敌有草间小黑蛛、大草蛉和肖蛸蛛,表明草间小黑蛛、大草蛉、肖蛸蛛等为棉蚜主要天敌优势种。     

各种天敌对棉蚜种群数量影响程度的研究

通过对１９８３、１９８４、１９８６、１９８８、１９９４和１９９５年６年棉花铃期以前棉蚜种群数量及其天敌种群数量的系统调查,并采用灰色关联分析法,研究各种天敌对棉蚜种群数量影响程度,得出龟纹瓢虫对棉蚜种群数量影响最大,其次是瓢虫类,第三是蜘蛛类．     

害虫与天敌个体数量比值对天敌竞争作用指数的影响——以茶园花蓟马及其主要天敌为例

为合理保护和利用自然天敌,明确害虫与天敌个体数量比值对天敌竞争作用指数(竞争系数和竞争强度指数)的影响。运用竞争系数分析法、灰色关联度分析法、竞争强度指数分析法和Pearson相关系数法对2020年、2021年三种茶园花蓟马与主要天敌个体数比值对主要天敌竞争作用指数的影响。三种茶园两年数据汇总分析得出,竞争系数和竞争强度指数均值与花蓟马-天敌比值的Pearson相关系数分别为-0.7858和-0.8199;2020年三种茶园数据综合分析得出,竞争系数和竞争强度指数均值与花蓟马-天敌比值的Pearson相关系数分别为-0.7391和-0.7819;2021年三种茶园竞争作用指数与比值的跟随关系不明显,主要是平阳特早茶园9种主要天敌以外的其他天敌影响了竞争作用趋势。综合多种分析结果得出,9种主要天敌的竞争作用指数与花蓟马-天敌比值呈显著负相关,其中三突花蟹蛛(-0.9936)负相关性最显著,鞍型花蟹蛛是高比值组竞争作用指数最高的天敌。研究结果为利用天敌开展花蓟马生物防治提供参考。     

自然生态系统公益及其价值

自然生态系统公益是指自然生态系统及其生态过程所形成的维持人类赖以生态的自然环境条件及其提供的服务.自然生态系统不但为人类提供食物、木材、燃料、纤维以及药物等社会经济发展的重要组成成分,而且还维持着人类赖以生存的生命支持系统,包括空气和水体的净化、缓解洪涝和干旱、土壤的产生及其肥力的维持、分解废物、生物多样性的产生和维持、气候的调节等,没有自然生态系统提供的这些公益人类文明将不再繁荣.人类经济的发展很大程度上依赖自然生态系统公益,但是人类工农业生产活动已经破坏了自然生态系统,如果继续当前的不合理生产方式,人类将在几十年内完全失去全球现有的自然生态系统公益.为了维持自然生态系统的可持续能力,更为了人类自身繁衍和发展,系统地认识并采取有效措施保持自然生态系统公益迫在眉睫.     

Invasion of a Top Predator into an Epipelagic Ecosystem can bring a Paradoxical Top-Down Trophic Control

We apply mathematical modeling to explore different scenarios of invasion of a top predator (carnivorous zooplankton or planktivorous fish) into an epipelagic plankton ecosystem. We use a ‘minimal’ model of three nonlinear ordinary differential equations (nutrient–phytoplankton–herbivores) with the top predator density as a time-dependent parameter. The ecosystem shows different types of response, which can be described in terms of top-down trophic control. Our investigation indicates that under certain conditions the plankton ecosystem model demonstrates a surprising kind of response: in a wide range of realistic ecosystem parameters the invasion of the top predator leads to a prominent increase in the average density of zooplankton and to a resulting decrease of phytoplankton density. This phenomenon is opposite to the ‘typical’ top–down control when the carnivore pressure decreases zooplankton density which, in turn, increases phytoplankton biomass. We call the revealed type of top-down control ‘paradoxical’. Examples of such a response in natural aquatic ecosystems were reported earlier but no clear explanation has been provided hitherto. In this paper, we analyze possible mechanisms of ‘paradoxical top–down control’ and show that it can occur in eutrophic epipelagic ecosystems subject to high rate of cross-pycnocline exchange.     

莫索湾垦区啮齿动物群落结构与物种多样性分析

2004年6～8月对莫索湾垦区啮齿动物调查,按不同生境共抽取18个样地,采用铗日法进行鼠类密度调查,共置10400个铗日,捕获啮齿动物446只,分属3科9属11种。经聚类分析,该垦区鼠类群落可划分为6种群落类型：（1）以大沙鼠（Rhombomys opimus）＋子午沙鼠（Meriones meridianus）为主的荒漠型;（2）以红尾沙鼠（Meriones erythrourus）＋小五趾跳鼠（Allactaga elater）为主的半荒漠灌丛型;（3）以柽柳沙鼠（Meriones tamariscinus）＋小林姬鼠（Apodemus sylvaticus）为主的林地型;（4）以小家鼠（Mus musculus）＋小林姬鼠为主的农田型;（5）以灰仓鼠（Cricetulus migratorius）＋子午沙鼠为主的弃耕地型;（6）以褐家鼠（Rattus norvegicus）为主的城镇型。从原始荒漠到城镇居民区的环境梯度变化中,鼠类群落多样性指数呈上升趋势（1．1053～1．2744）,到农田达到最大,农田到居民区则略有下降;均匀性随各群落生境类型不同,变化无规律性（0．6423≤J≤0．9207）;优势度则呈下降趋势（0．4176～0．3368）。生境差异、植被盖度和人为干扰强度对鼠类群落多样性均有一定影响。     

雷州半岛鼠形动物种群动态研究

雷州半岛鼠形动物种群动态研究肖文忠,莫冠英（广东省湛江鼠疫防治研究所５２４０３７）ＤｙｎａｍｉｃＲｅｓｅａｒｃｈｏｎＲｏｄｅｎｔＰｏｐｕｌａｔｉｏｎｓｉｎＬｅｉｚｈｏｕＰｅｎｉｎｓｕｌａ．￥ＸｉａｏＷｅｎｚｈｏｎｇ;ＭｏＧｕａｎｙｉｎｇ（Ｚｈａｎｊｉ...     

Predator Interference and the Establishment of Generalist Predator Populations for Biocontrol

We conducted a field experiment to determine the extent to which interference among generalist predators limits their effectiveness as biocontrol agents. We manipulated immigration of a guild of actively hunting generalist ground predators, carabid beetles and lycosid spiders, by intercepting them as they attempted to enter fenced 50-m² vegetable gardens. Immigration was blocked, allowed at the mean rate measured at our field site, or doubled. Altered immigration rates were maintained through a spring garden of cabbage, bean, eggplant, and cucumber, followed by a summer garden of squash. We monitored densities of carabids and lycosids to discover if altering their immigration rate changed their densities in the plots. We also measured densities of other predators on the ground and in plant foliage, pest numbers, and vegetable yields. Doubling the immigration rate of carabids and lycosids approximately doubled the densities of carabids inside the plots, but did not increase lycosid densities. Increasing the rate of immigration of carabids and lycosids depressed densities of nonlycosid ground spiders. In the spring gardens, manipulation of carabid and lycosid immigration did not influence numbers of predators or herbivores in the foliage and did not affect vegetable productivity. In contrast, in the summer gardens, foliage-dwelling predators were lower, pest densities were marginally lower, and squash productivity was higher in the carabid and lycosid immigration plots compared to the no-immigration treatment. Doubling carabid and lycosid immigration rate never increased the magnitude of their effects on other predators, pests, or plant productivity. Predator interference limited lycosid establishment, reduced densities of other predator taxa, and apparently prevented a doubling of carabid densities from having an increased impact on pest numbers. Nevertheless, despite widespread effects of predator interference, allowing immigration of lycosids and carabids increased squash productivity.     

村落生态系统的概念及特征

村落生态系统的概念及特征王智平,安萍（中国科学院石家庄农业现代化所,０５００２１）ＣｏｎｃｅｐｔａｔｉｏｎａｎｄＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＶｉｌｌａｇｅＥｃｏｓｙｓｔｅｍ．￥ＷａｎｇＺｈｉｐｉｎｇ;ＡｎＰｉｎｇ（ＩｎｓｔｉｔｕｔｅｏｆＡ－ｇｒ...     

农业生态系统中磷循环的研究进展

1　引　言能量转化和物质循环是农业生态系统最基本的功能特征。1976年在荷兰召开的第一次农业生态系统矿质养分循环研讨会标志着从系统层次研究物流的开始,但物流仍是系统研究的薄弱环节,特别是较高系统层次准确的物流的数量概念更为缺乏[1,2]。生态系统中营养元素的输入、输出状况反映了一个地区生产发展水平的高低和生态系统功能的强弱;而投入、产出的动态变化,则显示了一定时期内营养元素循环的基本规律[3]。在各种水平(如地球、陆地、国家或生态系统)上的有关磷循环的论文也发表了不少,借以阐述各组成部分中磷的数量及其相互间的转化速…     

Predator diversity strengthens trophic cascades in kelp forests by modifying herbivore behaviour

Although human-mediated extinctions disproportionately affect higher trophic levels, the ecosystem consequences of declining diversity are best known for plants and herbivores. We combined field surveys and experimental manipulations to examine the consequences of changing predator diversity for trophic cascades in kelp forests. In field surveys we found that predator diversity was negatively correlated with herbivore abundance and positively correlated with kelp abundance. To assess whether this relationship was causal, we manipulated predator richness in kelp mesocosms, and found that decreasing predator richness increased herbivore grazing, leading to a decrease in the biomass of the giant kelp Macrocystis. The presence of different predators caused different herbivores to alter their behaviour by reducing grazing, such that total grazing was lowest at highest predator diversity. Our results suggest that declining predator diversity can have cascading effects on community structure by reducing the abundance of key habitat-providing species.     

生态系统稳定性研究的历史与现状

生态系统稳定性研究的历史与现状刘增文李雅素（西北林学院,陕西杨陵７１２１００）ＨｉｓｔｏｒｙａｎｄＳｔａｔｕｓｏｆＲｅｓｅａｒｃｈｏｆＥｃｏｓｙｓｔｅｍＳｔａｂｉｌｉｔｙ．ＬｉｕＺｅｎｇｗｅｎ,ＬｉＹａｓｕ（ＮｏｒｔｈｗｅｓｔｅｒｎＣｏｌｅｇｅｏｆＦ...